1. Field of the Invention
The present invention relates to the technical field of agricultural sprayers. It relates more particularly to a method for switching a water circuit with which such a machine is equipped, to allow said water circuit to be configured in the xe2x80x9cinductionxe2x80x9d mode.
Agricultural sprayers are used for spreading a treatment spray mix in the form of droplets onto plants. For this purpose, said sprayers include various elements connected to one another by a water circuit. These elements are, in particular, a main tank containing the spray mix, and spray nozzles intended to spread said spray mix over the plants that are to be treated. Spraying consists in pumping the spray mix, using the water circuit, from the main tank to the nozzles, while at the same time moving said nozzles with respect to the plants that are to be treated.
Before actually carrying out the spraying, the user has, amongst other things, to prepare the treatment spray mix. Now, for obvious storage reasons, the active compound of the spray mix is generally packaged in the form of concentrate in cans. Preparing the spray mix therefore consists in diluting one or more active compounds, for example plant protection products, in water. To do this, and for user-safety reasons, most agricultural sprayers also include an induction unit. This may be fixed or moveable with respect to the sprayer and is preferably accessible from the ground. The induction unit is made up of a tub into which the user tips the cans of active compound. When preparing the spray mix, the tub is emptied into the main tank via the water circuit.
After spraying, it is necessary to rinse all the elements which have been in contact with the treatment spray mix. This is because said spray mix tends, when it is stagnant, to form a deposit that is detrimental to the correct operation of said sprayer. To this end, most sprayers additionally include a reserve of water stored in a rinsing tank. Rinsing consists in pumping this reserve of water, via the water circuit, from said rinsing tank to the sullied elements. The spray mix residue, highly diluted in the rinsing water, is finally expelled onto said plants via the spray nozzles.
In general, the water circuit of an agricultural sprayer also allows the main tank to be filled by pumping water from a river, for example. In addition it is common place for said water circuit also to allow said main tank to be emptied by transferring the treatment spray mix to an external tank.
In order to perform the various functions listed hereinabove, the water circuit includes at least one pump, a set of pipes and several valves. In a way known to the person skilled in the art, the position of said valves determines the type of function performed by the water circuit (xe2x80x9csprayingxe2x80x9d, xe2x80x9cinductionxe2x80x9d, xe2x80x9crinsingxe2x80x9d, xe2x80x9cfillingxe2x80x9d, xe2x80x9cemptyingxe2x80x9d).
2. Discussion of the Background
With most agricultural sprayers currently on the market and in particular the sprayer described in patent application WO 95/03 688, the user configures the water circuit by manipulating each of the valves individually so as to position these valves in accordance with a layout corresponding to the desired function. Now, an agricultural sprayer generally has a great many valves, and each valve can be oriented into at least two different positions. Configuring such a water circuit, that the user changes each time there is a change in function, therefore constitutes a relatively great loss of time. In addition, with this type of manipulation, the risk of error in positioning the valves or quite simply the risk of forgetting to orient a valve, is not inconsiderable. In such an instance, the function performed by the water circuit is not the one desired by the user. The consequence of this may, for example, be loss of said active compound.
In order to solve this problem, patent application FR 2,714,572 describes an agricultural sprayer in which some valves of the water circuit are operated by a control unit. With this known sprayer, the user first of all selects the function that is to be performed, by means of a selector. Then, the control element electrically drives various valves of the water circuit so as to configure the latter in the appropriate mode. However, the use of such a solution probably leads to a not insignificant manufacturing on-cost. In addition, this solution still entails the intervention of the user, for example when preparing the treatment spray mix, to indicate the type of function to be performed. In consequence, the risks of error are not eliminated. For example, the user may forget to select the xe2x80x9cinductionxe2x80x9d function. He may just as easily select the wrong function.
The object of the present invention is therefore to remedy the various drawbacks of the state of the art by proposing a solution for an agricultural sprayer comprising a moving induction unit, so as to eliminate any risk of oversight and error in manipulation when configuring the water circuit in the xe2x80x9cinductionxe2x80x9d mode.
Accordingly, there is proposed a method for switching the configuration of a water circuit of an agricultural sprayer to xe2x80x9cinductionxe2x80x9d mode, said sprayer including an induction unit capable of occupying at least one transport position and at least one filling position, wherein a movement of said induction unit from a transport position into a filling position switches the configuration of said water circuit to the xe2x80x9cinductionxe2x80x9d mode. With agricultural sprayers including a moving induction unit and when preparing the spray mix, the user brings the induction unit into a filling position so as to make it easier to tip the cans of active compound. With the switching method of the present invention, this action prior to any induction has the effect of automatically, and therefore quickly, configuring the water circuit of the sprayer for the appropriate function. As the user no longer operates said valves manually, the risk of oversight and errors of manipulation are therefore eliminated.
The present invention also relates to an agricultural sprayer for implementing this switching method. Said sprayer therefore includes a moving induction unit and a water circuit configured by valves. According to another feature of the present invention, the movement of the induction unit acts directly on the valves involved in configuring the water circuit in the xe2x80x9cinductionxe2x80x9d mode. In consequence, the means for implementing the method of the present invention are simple and therefore inexpensive.